Coomon pages on all languages

Hi

We are testing the plugin on a our website and we urgently need help on most practical problem.
we have 3 languages on our website but many pages have no translation for each page/post. So we are thinking a way to add these pages with just one language (these pages are common to all languages) How do we do that? because it is a must to have a default language.

my requirement has been discussed on this forum too (https://www.ads-software.com/support/topic/make-post-available-in-all-languages/#post-8944831)

Can you please help us to find a solution?